Light sources with chip-level integrated diffusers

ABSTRACT

An embodiment includes a light source. The light source may include a substrate and a diffuser. The substrate may include a first surface and a second surface. The second surface may be opposite the first surface. The diffuser may be carried by the substrate. The diffuser may be configured to receive an optical signal from the substrate after the optical signal propagates through the substrate and to control a particular profile of a resultant beam of the optical signal over two axes after the optical signal propagates through the integrated diffuser.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.15/867,546 filed on Jan. 10, 2018 and claims priority to and the benefitof U.S. Provisional Application No. 62/444,607 filed on Jan. 10, 2017.The contents of these applications are incorporated herein by referencein their entirety.

FIELD

The embodiments discussed in the present disclosure are related to lightsources with chip-level integrated diffusers.

BACKGROUND

Unless otherwise indicated herein, the materials described herein arenot prior art to the claims in the present application and are notadmitted to be prior art by inclusion in this section.

Some illumination functions benefit from a light source that issubstantially uniform in its profile. For example, a user may want toengineer the profile to be 30 degrees divergent in the horizontaldirection and 50 degrees in the vertical direction so a rectangular areais illuminated in the far field. Light sources implemented in suchillumination functions may include a diffuser or an engineered diffuser.The diffuser may control divergence of the profile of the light source.However, in these light sources the diffuser or the engineered diffuseris included in a package at some distance away from an optical source.Accordingly, including the diffusers in these light sources involvespackage-level integration and costs associated with the packageintegration.

The subject matter claimed herein is not limited to implementations thatsolve any disadvantages or that operate only in environments such asthose described above. Rather, this background is only provided toillustrate one example technology area where some implementationsdescribed herein may be practiced.

SUMMARY

This Summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential characteristics of the claimed subject matter, nor is itintended to be used as an aid in determining the scope of the claimedsubject matter.

In one embodiment, a light source includes a substrate including a firstsurface and a second surface positioned opposite the first surface. Thelight source also includes an epitaxy layer positioned on the firstsurface of the substrate, an optical element formed in the epitaxylayer, the optical element positioned such that an optical signaltransmitted thereby is directed toward the substrate, and a diffuserconfigured to receive the optical signal and to control a particularprofile of a resultant beam of the optical signal after the opticalsignal propagates through the diffuser. The diffuser includes aplurality of lenslets carried by the substrate, and one or more of thelenslets is refractive or diffractive.

In another embodiment, a light source includes a substrate including afirst surface and a second surface positioned opposite of the firstsurface and being configured for an optical signal to pass therethrough.The light source also includes a diffuser configured to receive anoptical signal and to control a particular profile of a resultant beamof the optical signal over two axes after the optical signal propagatesthrough the diffuser. The diffuser is carried by the substrate andincludes a plurality of lenslets pseudorandomly arranged relative to oneanother.

In another embodiment, a method includes growing an epitaxy layer on afirst surface of a substrate, the substrate including the first surfaceand a second surface positioned opposite the first surface. The methodalso includes forming an optical element in the epitaxy layer such thatan optical signal transmitted by the optical element is directed towardthe substrate, and pseudorandomly arranging a plurality of lenslets onthe substrate. The plurality of lenslets are configured to receive theoptical signal transmitted by the optical element and to control aparticular profile of a resultant beam of the optical signal after theoptical signal propagates through the lenslets.

Additional features and advantages of the invention will be set forth inthe description which follows, and in part will be obvious from thedescription, or may be learned by the practice of the invention. Thefeatures and advantages of the invention may be realized and obtained bymeans of the instruments and combinations particularly pointed out inthe appended claims. These and other features of the present inventionwill become more fully apparent from the following description andappended claims, or may be learned by the practice of the invention asset forth hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

To further clarify the above and other advantages and features of thepresent invention, a more particular description of the invention willbe rendered by reference to specific embodiments thereof which areillustrated in the appended drawings. It is appreciated that thesedrawings depict only typical embodiments of the invention and aretherefore not to be considered limiting of its scope. The invention willbe described and explained with additional specificity and detailthrough the use of the accompanying drawings in which:

FIG. 1 is a block diagram of a light source;

FIG. 2A illustrates a block diagram of an example light source;

FIG. 2B illustrates another block diagram of the light source of FIG.2A;

FIG. 2C illustrates another block diagram of the light source of FIGS.2A and 2B;

FIG. 3 illustrates a block diagram of another example light source;

FIG. 4 illustrates a block diagram of another example light source;

FIG. 5A illustrates a block diagram of another example light source;

FIG. 5B illustrates a block diagram of another example light source;

FIG. 6A illustrates a block diagram of another example light source;

FIG. 6B illustrates a block diagram of another example light source;

FIG. 6C illustrates a block diagram of another example light source;

FIG. 7 depicts an example integrated diffuser polymer;

FIGS. 8A-8H illustrate example particular profiles;

FIG. 9 is a flow chart that depicts an example method of chip-leveldiffuser integration in a light source; and

FIG. 10 is a flow chart that depicts another example method ofchip-level diffuser integration in a light source.

DETAILED DESCRIPTION

Reference will now be made to the drawings to describe various aspectsof example embodiments of the invention. It is to be understood that thedrawings are diagrammatic and schematic representations of such exampleembodiments, and are not limiting of the present invention, nor are theynecessarily drawn to scale.

FIG. 1 is a block diagram of an example light source 50 that may beconfigured for one or more illumination functions. The light source 50may include an optical element 56 that transmits an optical signal 51.The optical signal 51 may propagate to a diffuser 52. As the opticalsignal 51 propagates to the diffuser 52, the optical signal 51 maydiverge. As the optical signal 51 diverges, it may have a substantiallyuniform cross-sectional area. The uniform cross-sectional area (e.g.,circular) may be substantially parallel to the YZ-plane of thearbitrarily-defined coordinate system of FIG. 1.

To modify the optical signal 51 from the substantially uniform profileto another particular profile, the diffuser 52 may be placed at somedistance 53 from the optical element 56. The diffuser 52 may include apiece of plastic or a piece of glass that is configured to receive theoptical signal 51 having the substantially uniform profile and change itto another profile. The diffuser 52 may be configured to change theprofile of the optical signal 51 from the substantially uniform profileto another profile. For instance, a resultant beam 54 exiting thediffuser 52 may have a particular profile in the far field such as 30degrees divergent in the horizontal direction (e.g., x-direction) and 50degrees in the vertical direction (e.g., y-direction) or anotherparticular profile.

The diffuser 52 in the light source 50 is added at the distance 53 fromthe optical element 56. Accordingly, the addition of the diffuser 52 maybe a package-level addition to the light source 50. For example, anexterior shell or package may be configured to receive a substrate 55and the optical element 56 as an integrated component. The diffuser 52may then be added to the package. For example, the shell or the packagemay include a ceramic package. The diffuser 52 may be adhered to a topsurface of the ceramic package.

Package-level additions may refer to multiple components that areseparate structures and that are installed in a package relative to oneanother. For example, the light source 50 includes two package-levelcomponents: the diffuser 52 and the substrate 55 with the opticalelement 56. The substrate 55 and the optical element 56 may be referredto as integrated at a chip level, which may also be referred to aswafer-level integration.

For example, the wafer-level integration indicates that the opticalelement 56 and the substrate 55 are formed using wafer-level processthat forms the optical element 56 and the substrate 55 into a singlechip structure. The diffuser 52 is not included in the chip structurewith the optical element 56 and the substrate 55 and not installedrelative to the optical element 56 and the substrate 55 using awafer-level process.

In some embodiments, a portion of the optical signal 51 may betransmitted through the substrate 55. In these and other embodiments,the optical element 56 may be positioned at a surface of the substrate55 opposite a surface 57. The optical signal 51 may then propagatethrough the substrate 55, exit the substrate 55, and propagate throughthe diffuser 52. In these embodiments, the diffuser 52 may be separatedfrom the substrate 55 by the distance 53 and operate as described above.

FIGS. 2A-2C illustrate block diagrams of an example light source 100.The light source 100 includes an integrated diffuser 110. The integrateddiffuser 110 may be positioned on a second surface 116 of a substrate106 and integrated at a chip-level with the substrate 106 and an opticalelement 104. FIG. 2A depicts a side-sectional view of the light source100. FIG. 2B depicts a front view of the light source 100. FIG. 2Cdepicts another front view of the light source 100 at the second surface116.

With reference to FIG. 2A, the light source 100 may be an example of aback-side emitting light source. In back-side emitting light sources,the optical element 104 may be positioned on a first surface 118 of thesubstrate 106. The optical element 104 may be configured to transmit anoptical signal 112 such that the optical signal 112 propagates throughthe substrate 106. In FIG. 2A, the optical signal 112 is transmitted inthe positive x-direction of the arbitrarily-defined coordinate system ofFIG. 2A.

The optical element 104 may be formed in an epitaxy layer 108. Theepitaxy layer 108 may be formed on the first surface 118. Additionally,one or more contacts 102 may be formed on the epitaxy layer 108 throughwhich electrical signals may be communicated to the optical element 104.

In the depicted embodiment, the optical element 104 includes a back-sideemitting optical source. For instance, the optical element 104 mayinclude a substrate-emitting vertical-cavity surface-emitting laser(VCSEL), which may be formed in the epitaxy layer 108 on the firstsurface 118.

In some embodiments, the optical element 104 may include an array ofVCSELs. The array of VCSELs may include multiple, individual VCSELs thatare arranged to transmit the optical signal 112. The number of VCSELsmay be based on a particular application in which the light source 100is included. For instance, in some embodiments, the array of VCSELs mayinclude many hundreds (e.g., one thousand or more) of the VCSELs.

In these and other embodiments, the VCSELS of the array of VCSELs may bearranged in a pattern. The pattern of the VCSELS may be repetitiveand/or may be arranged in a pattern that is symmetric about at least oneaxis. For example, in FIGS. 2A and 2B, the VCSELs in the array of VCSELsmay be arranged in a rectangular pattern that is symmetric about axesthat are substantially parallel to the x-axis and/or the y-axis.Alternatively, in these and other embodiments, the VCSELs of the arrayof VCSELs may be arranged in a non-repeating and/or non-symmetricpattern. For example, the VCSELs may be arranged in a random pattern ora pseudo-random pattern.

The optical signal 112 is generated by the optical element 104. Theoptical element 104 may be configured such that the optical signal 112propagates through the substrate 106 (e.g., from the first surface 118to the second surface 116). As the optical signal 112 propagates throughthe substrate 106, dimensions of the optical signal 112 may change. Forinstance, in the depicted embodiment, a diameter or a dimension in the ydirection of the optical signal 112 may increase as the optical signal112 propagates through the substrate 106.

The optical signal 112 may exit the substrate 106 at the second surface116. The integrated diffuser 110 may be positioned directly on thesecond surface 116. For example, a surface of the integrated diffuser110 and the second surface 116 may be in direct physical contact withone another such that the optical signal 112 propagates directly fromthe substrate 106 to the integrated diffuser 110. Additionally oralternatively, the integrated diffuser 110 may be formed such that thereis no distinction between the integrated diffuser 110 and the secondsurface 116 of the substrate 106. Accordingly, the optical signal 112propagates through the integrated diffuser 110 after the optical signal112 exits the substrate 106 at the second surface 116.

The integrated diffuser 110 is configured to control a particularprofile 121 of a resultant beam 114 of the optical signal 112 after theoptical signal 112 propagates through the integrated diffuser 110.Control of the particular profile of the resultant beam 114 may includediverging the optical signal 112, converging the optical signal 112,collimating of the optical signal 112, or some combinations thereof.Additionally, control of the particular profile of the resultant beam114 may include control in two axes. For example, the particular profileof the resultant beam 114 may be controlled such that the particularprofile includes a first dimension in a first direction that is alignedwith a first of the two axes (e.g., the first direction may be parallelwith the y-axis) and a second dimension in a second direction that isaligned with a second of the two axes (e.g., the second direction may beparallel to the z-axis).

The substrate 106 includes the first surface 118 and the second surface116. The second surface 116 is opposite the first surface 118 in theembodiment of FIG. 2A. The substrate 106 may be comprised of variousmaterials or combination of materials. The material(s) of the substrate106 may dictate and/or may be selected to accommodate a wavelength ofthe optical signal 112.

For example, in some embodiments, the substrate 106 may be comprised ofgallium arsenide (GaAs). A GaAs substrate may be suitable in embodimentsin which the optical signal 112 has a wavelength within the infrared(IR) spectrum such as a wavelength greater than about 900 nanometers(nm) (e.g., about 940 nm). In other embodiments, the substrate 106 maybe comprised of indium phosphide. In these and other embodiments, thewavelength of the optical signal 112 may be longer than the wavelengthsof embodiments using GaAs substrates. In yet other embodiments, thesubstrate 106 may be comprised of gallium nitride, silicon carbide, orsapphire. In these and other embodiments, the optical signal 112 mayhave a wavelength that may be in a blue spectrum. In yet otherembodiments, the optical signal 112 may have a wavelength of about 1300nm.

The integrated diffuser 110 may include lenslets 111. In FIGS. 2A-2C,only one of the lenslets 111 is labelled. The lenslets 111 areconfigured to provide the particular profile of the resultant beam 114.For example, one or more characteristics of the lenslets 111 and thearrangement of the lenslets 111 on the second surface 116 can bedetermined such that the particular profile results.

The lenslets 111 may be positioned at multiple locations on the secondsurface 116. The lenslets 111 may include one or more lenslets that arerefractive. Additionally, the lenslets 111 may include one or morelenslets that are diffractive. In some embodiments, the lenslets 111 maybe positioned at pseudorandom locations on the second surface 116.Additionally or alternatively, the lenslets 111 may include two or morefocal lengths. The two or more focal lengths of the lenslets 111 may bepseudorandom. For example, the lenslets 111 may include five individuallenslets, each of which may have a different focal length. The fiveindividual lenslets may be positioned on the second surface 116pseudorandomly. Accordingly, the pseudorandom positioning of the fiveindividual lenslets having different focal lengths may result in theintegrated diffuser 110 having in the aggregate a pseudorandomdistribution on the second surface 116.

The lenslets 111 may also include one or more conical shapes and/or oneor more cylindrical shapes. The conical shapes and/or the cylindricalshapes include a refraction that in the aggregate controls divergence ofthe resultant beam. Examples of the conical shapes may include cones,elliptical cones, cylinders (e.g., cone with an apex at infinity),domes, and the like.

The lenslets 111 may be arranged on the second surface 116 in aparticular pattern and/or may be sized relative to the optical signal112 at the second surface 116. The particular pattern may be repetitiveor otherwise configured such that the optical element 104 need not beprecisely aligned with the integrated diffuser 110. For example, in somelight sources (e.g., the light source 50 of FIG. 1) an optical sourcemay be precisely aligned with a lens, which may enable the lens tomodify or focus light passing through the lens. Misalignment between theoptical source and the lens may result in the light being poorlyfocused. However, the multiple lenslets 111 may not have to be preciselyaligned. For instance, in embodiments in which the lenslets 111 arepseudorandomly positioned with pseudorandomly focal lengths may enablean imprecise alignment between the optical element 104 and theintegrated diffuser 110.

FIG. 2C illustrates a block diagram of the light source 100 of FIG. 2A.In FIG. 2C, an end view of the light source 100 is depicted with theintegrated diffuser 110 removed. Referring to FIGS. 2A and 2C, thelenslets 111 may be sized such that the optical signal 112 at the secondsurface 116 impinges multiple lenslets 111. In addition, a diameter 120of the optical signal 112 at the second surface 116 may be sized toimpinge multiple of lenslets 111 as it exits the substrate 106. Forinstance, in some embodiments, the lenslets 111 may include diameters ina range of about one-half micron to about five microns. The diameter 120may be about thirty microns. Accordingly, the optical signals 112 mayimpinge at least about six lenslets 111 and up to about sixty lenslets111. In other embodiments, the diameters of the lenslets 111 may belarger than five microns or smaller than one-half microns. Additionally,the optical signal 112 at the second surface 116 may be smaller thansixty microns or larger than sixty microns. In some embodiments, thelenslets 111, the substrate 106, and the optical signal 112 may beconfigured such that at least ten lenslets 111 are impinged by theoptical signal 112 at the second surface 116.

Referring to FIG. 2B, the particular profile 121 of the resultant beam114 may be controlled over two axes. For instance, with reference toFIGS. 2A-2C, the particular profile 121 of the resultant beam 114 may becontrolled in a first direction 123 that is parallel to the y-axis and asecond direction 125 that is parallel to the z-axis. For example, thelenslets 111 may be designed and arranged on the second surface 116 suchthat the particular profile 121 of the resultant beam 114 includes afirst dimension along the first direction 123 and a second dimension inthe second direction 125. The first dimension may differ from the seconddimension. In other embodiments, the particular profile 121 may includeother shapes. Some additional details of the other particular profilesare provided with reference to FIGS. 8A-8H.

In the depicted embodiment, the optical signal 112 at the second surface116 may be substantially circular as depicted in FIG. 2C. As the opticalsignal 112 passes through the integrated diffuser 110, the particularprofile 121 of the resultant beam 114 may be controlled such that theparticular profile 121 is rectangular as depicted in FIG. 2B. In thedepicted embodiment, the integrated diffuser 110 controls diversion ofthe optical signal 112 to result in the particular profile 121. In otherembodiments, the integrated diffuser 110 may control conversion orcollimation of the optical signal.

The integrated diffuser 110 may be implemented with the substrate 106and the optical element 104 at the chip-level. For instance, integrateddiffuser 110 is implemented directly on the substrate 106 such that thesubstrate 106, the epitaxy layer 108, and the optical element 104 areincluded in a single chip. The integrated diffuser 110, the substrate106, the epitaxy layer 108, and the optical element 104 may beconstructed using wafer-level integration processes.

Referring to FIGS. 1-2C, a benefit of the light source 100 of FIGS.2A-2C compared to the light source 50 of FIG. 1 may include a reductionin costs associated with a second-level package integration. Inaddition, a benefit of the light source 100 compared to the light source50 may include facilitation of integration of the light source 100 intovarious applications. For example, the light source 100 may be smallerand a single package that may enable the light source 100 to be moreeasily integrated into devices and applications.

FIG. 3 illustrates a block diagram of another example light source 200.The light source 200 includes the optical element 104 positioned on thefirst surface 118 of the substrate 106. The optical element 104 may beconfigured to transmit the optical signal 112 such that the opticalsignal 112 propagates through the substrate 106. The optical signal 112exits the substrate 106 and directly enters an etched integrateddiffuser 210. The etched integrated diffuser 210 is positioned directlyon the second surface 116 and is configured to control the particularprofile of the resultant beam 114 of the optical signal 112 as it exitsthe substrate 106 and propagates through the etched integrated diffuser210.

In the embodiment of FIG. 3, the etched integrated diffuser 210 isetched directly into the second surface 116 of the substrate 106. Forinstance, the epitaxy layer 108 may be formed on the first surface 118of the substrate 106 with the optical element 104 included therein. Theetched integrated diffuser 210 (e.g., multiple lenslets 111) may then beetched into the substrate 106. The etched integrated diffuser 210 mayoperate substantially similarly to the integrated diffuser 110 describedwith reference to FIGS. 2A-2C. However, the integrated diffuser 210 isformed through one or more material removal processes applied to thesecond surface 116. The etched integrated diffuser 210 may include thelenslets 111 described above.

FIG. 4 illustrates a block diagram of another example light source 300.The light source 300 includes the optical element 104 positioned on thefirst surface 118 of the substrate 106. The optical element 104 may beconfigured to transmit the optical signal 112 such that the opticalsignal 112 propagates through the substrate 106. The optical signal 112exits the substrate 106 and directly enters a polymer integrateddiffuser 310. The polymer integrated diffuser 310 is positioned directlyon the second surface 116 and is configured to control the particularprofile of the resultant beam 114 of the optical signal 112 as it exitsthe substrate 106 and propagates through the polymer integrated diffuser310.

In the embodiment of FIG. 4, the polymer integrated diffuser 310 isformed on a polymer. The polymer integrated diffuser 310 is attached tothe second surface 116 of the substrate 106. For example, FIG. 7 depictsan example integrated diffuser polymer (“polymer”) 700. For instance,the epitaxy layer 108 may be formed on the first surface 118 of thesubstrate 106 with the optical element 104 included therein. The polymerintegrated diffuser 310 may then be formed in the polymer 700 andattached onto the second surface 116 of the substrate 106. Theintegrated diffuser 310 may operate substantially similarly to theintegrated diffusers 110 and 210 described with reference to FIGS. 2A-3.The polymer integrated diffuser 310 may include the lenslets 111described above.

With combined reference to FIGS. 4 and 7, lenslets 702 may be formed inthe polymer 700 either prior to or following attachment of the polymer700 to the substrate 106. In FIGS. 4 and 7, only one of the lenslets 702is labeled. The lenslets 702 are substantially similar to the lenslets111 described with reference to FIGS. 2A-2C.

In some embodiments, the polymer integrated diffuser 310 is comprised ofan ultra violet (UV) curable polymer. In these and other embodiments,the polymer integrated diffuser 310 is generated using a master UVstamp. Alternatively, in some embodiments, the polymer integrateddiffuser 310 may be comprised of a thermoplastic. In these and otherembodiments, the polymer integrated diffuser 310 may be generated usinga heated stamp that melts a surface of the thermoplastic. Alternativelystill, in some embodiments, the polymer integrated diffuser 310 may begenerated using lithography.

FIGS. 5A and 5B illustrate a block diagrams of other example lightsources 400A and 400B. The light sources 400A and 400B include theoptical element 104 positioned on the first surface 118 of the substrate106 that is configured to transmit the optical signal 112 such that theoptical signal 112 propagates through the substrate 106. The lightsources 400A and 400B of FIGS. 5A and 5B include mixed integrateddiffusers 410 and 411 respectively. The mixed integrated diffusers 410and 411 may be positioned on the second surface 116 and may beconfigured to control a particular profile of the resultant beam 114 ofthe optical signal 112 as it exits the substrate 106 and propagatesthrough the mixed integrated diffusers 410 and 411. The mixed integrateddiffusers 410 and 411 may operate substantially similarly to theintegrated diffuser 110 described with reference to FIGS. 2A-2C.

In the embodiment of FIG. 5A, the mixed integrated diffuser 410 includesa first portion 410A and a second portion 410B. The first portion 410Aof the integrated diffuser 410 is formed on a polymer (e.g., the polymer700 described below) that is attached to the second surface 116 of thesubstrate 106. The second portion 410B of the mixed integrated diffuser410 may be etched directly into the second surface 116 of the substrate106.

In the embodiment of FIG. 5B, the integrated diffuser 411 includes afirst portion 411A and a second portion 411B. The first portion 411A isetched directly into the second surface 116 of the substrate 106. Thesecond portion 411B of the integrated diffuser 411 is formed on apolymer (e.g., 700) that is attached to the first portion 411A. Forexample, the second portion 411B may be overlaid on the first portion411A. The first portion 411A and the second portion 411B may havecomplementary effects. For example, the first portion 411A may include afirst shape providing diffusion in the z-direction and the secondportion 411B may include a second shape providing diffusion in they-direction. In these and other embodiments, the complementary effectsmay be at least partially due to the refractive index of thesemiconductor material of the substrate 106 being high such thatrefraction occurs at the semiconductor-polymer interface between thefirst portion 411A and the second portion 411B, and then again at thepolymer-air interface between the second portion 411B and a surroundingenvironment.

FIGS. 6A-6C illustrate block diagrams of example light sources600A-600C. The light sources 600A-600C include the optical element 104positioned on the first surface 118 of the substrate 106. The opticalelement 104 may be configured to transmit the optical signal 112 suchthat the optical signal propagates through the substrate 106. The lightsources 600A-600C of FIGS. 6A-6C include integrated diffusers 610A,610B, 610C, respectively. The integrated diffusers 610A, 610B, 610Cfunction substantially similarly to the integrated diffuser 110described with reference to FIGS. 2A-2C. The integrated diffusers 610A,610B, 610C may be constructed similarly to the etched integrateddiffuser 210 of FIG. 3, the polymer integrated diffuser 310 of FIG. 4,or the mixed integrated diffusers 410 and 411 of FIGS. 5A and 5B.

The integrated diffusers 610A, 610B, 610C are positioned directly on thesecond surface 116 and are configured to control divergence orconvergence of the resultant beam 114 of the optical signal 112 as itexits the substrate 106. In particular, a first integrated diffuser 610Aof FIG. 6A may be configured to diverge the optical signal 112. Forexample, an angle 612 between an outer edge 614 of the resultant beam114 and the second surface 116 may be greater than 90 degrees.Additionally, the angle 612 may be greater than an impingement angle 616between an outer edge 618 of the optical signal 112 and the secondsurface 116. The angle 612 may range between about 90 degrees and about180 degrees.

Referring to FIG. 6B, a second integrated diffuser 610B may beconfigured to project the optical signal 112. For example, an angle 619between the outer edge 614 of the resultant beam 114 and the secondsurface 116 may be equal to 90 degrees.

Referring to FIG. 6C, a third integrated diffuser 610C may be configuredto converge the optical signal 112. For example, an angle 620 betweenthe outer edge 614 of the resultant beam 114 and the second surface 116may be less than 90 degrees. Additionally, the angle 620 may be lessthan an impingement angle 622 between the outer edge 618 of the opticalsignal 112 and the second surface 116. The angle 620 may range betweenabout 90 degrees and about 15 degrees.

FIGS. 8A-8H illustrate example particular profiles 800A-800H. Theparticular profiles 800A-800H may be generated by an integrated diffusersuch as the integrated diffusers 110, 210, 310, 410, 411, and 610A-610Cdescribed elsewhere in the present disclosure. In the particularprofiles 800A-800H the patterned portion indicates portions of theparticular profiles 800A-800H that are illuminated. Each of theparticular profiles 800A-800H is briefly described in the followingparagraphs.

FIG. 8A includes a first particular profile 800A. The first particularprofile 800A includes multiple horizontal lines 802A-802D that areseparated by non-illuminated portions 804A-804C. The width (a dimensionin the x-direction) of the horizontal lines 802A-802D, width (adimension in the x-direction) of the non-illuminated portions 804A-804C,height (a dimension in the y-direction) of the horizontal lines802A-802D, height of the non-illuminated portions 804A-804C, number ofthe non-illuminated portions 804A-804C, number of the horizontal lines802A-802D, or any combination thereof may be determined by theintegrated diffuser.

FIG. 8B includes a second particular profile 800B. The second particularprofile 800B includes multiple vertical lines 801A-801D that areseparated by non-illuminated portions 803A-803C. The width (a dimensionin the x-direction) of the vertical lines 801A-801D, the width (adimension in the x-direction) of the non-illuminated portions 803A-803C,the height (a dimension in the y-direction) of the vertical lines801A-801D, the height of the non-illuminated portions 803A-803C, thenumber of the non-illuminated portions 803A-803C, the number of thevertical lines 801A-801D, or any combination thereof may be dictated bythe arrangement and characteristics of an integrated diffuser.

FIG. 8C includes a third particular profile 800C. The third particularprofile 800C includes one horizontal line 806. A width (a dimension inthe x-direction) of the horizontal line 806 and/or a height (a dimensionin the y-direction) of the horizontal line 806 may be dictated by thearrangement and characteristics of an integrated diffuser. FIG. 8Dincludes a fourth particular profile 800D. The fourth particular profile800D includes one vertical line 808. A width (a dimension in thex-direction) of the vertical line 808 and/or a height (a dimension inthe y-direction) of the vertical line 808 may be dictated by thearrangement and characteristics of an integrated diffuser.

FIG. 8E includes a fifth particular profile 800E. The fifth particularprofile 800E includes a rectangular block 810. A width (a dimension inthe x-direction) of the rectangular block 810 and/or height (a dimensionin the y-direction) of the rectangular block 810 may be dictated by thearrangement and characteristics of an integrated diffuser. For instance,the rectangular block 810 may change and include dimensions of thefourth or third particular profiles 800C and 800D.

FIG. 8F includes a sixth particular profile 800F. The sixth particularprofile 800F includes a circular profile 812. A diameter 814 of thecircular profile 812 may be dictated by the arrangement andcharacteristics of an integrated diffuser. FIG. 8G includes a seventhparticular profile 800G. The seventh particular profile 800G includes amulti-circular profile 816. One or both of the diameters 818 of themulti-circular profile 816 and/or the number of circles included in themulti-circular profile 816 may be dictated by the arrangement andcharacteristics of an integrated diffuser. For example, themulti-circular profile 816 may include two or more circles. FIG. 8Hincludes an eighth particular profile 800H. The eighth particularprofile 800H includes an oval profile 820. Foci lengths of the ovalprofile 820 may be dictated by the arrangement and characteristics of anintegrated diffuser.

To generate the first particular profile 800A, the second particularprofile 800B, and the seventh profile 800G, refractive optics and/ordiffractive optics may be integrated with one or more of the integrateddiffusers 110, 210, 310, 410, 411, and 610A-610C described elsewhere inthis disclosure. In these embodiments, the refractive optics and/or thediffractive optics may be aligned relative to the optical element 104with precision.

With combined reference to FIGS. 2A-8H, the light sources (e.g., 100,200, 300, 400A, 400B, and 600A-600C) described in this disclosure may beconfigured for various applications. In particular, the particularprofile may be configured to illuminate a particular volume in the farfield or portion of the particular volume. For example, the lightsources (e.g., 100, 200, 300, 400A, 400B, and 600A-600C) may beimplemented in various applications such as a night vision illuminator,an IR illuminator, a parking sensor, a driver alertness sensor, anothersensor, or a similar application. In the various applications the lightsources (e.g., 100, 200, 300, 400A, 400B, and 600A-600C) may besubstituted for an existing light source currently in these applicationsthat may be similar to the light source 50 of FIG. 1.

FIG. 9 is a flow chart of an example method 900 of chip-levelintegration of a diffuser in a light source according to at least oneembodiment described in the present disclosure. Although illustrated asdiscrete blocks, various blocks in FIG. 900 may be divided intoadditional blocks, combined into fewer blocks, or eliminated, dependingon the desired implementation.

The method 900 may begin at block 902 in which an epitaxy layer may begrown. The epitaxy layer may be grown on a first surface of a substrate.The substrate may include the first surface and a second surface that isopposite the first surface. At block 904, one or more optical elementsmay be formed in the epitaxy layer. The one or more optical elements maybe formed in the epitaxy layer such that optical signals transmitted bythe one or more optical elements propagate through the substrate in adirection towards the second surface.

At block 906, at least a portion of an integrated diffuser may be etcheddirectly into the second surface of the substrate. For example, theintegrated diffuser may be etched using wet etching, plasma etching oranother suitable type of etching. At block 908, a polymer overlay may beoverlaid. The polymer overlay may be overlaid on an outer surface of theetched portion of the integrated diffuser. In some embodiments, block908 or any other block may be skipped.

At block 910, the integrated diffuser may be positioned directly on thesecond surface. The integrated diffuser may be positioned on the secondsurface such that the integrated diffuser is configured to receive thetransmitted optical signals directly from the substrate after theoptical signal propagates through the substrate and to control aparticular profile of a resultant beam of the optical signal after theoptical signal propagates through the integrated diffuser.

One skilled in the art will appreciate that, for this and otherprocedures and methods disclosed herein, the functions performed in theprocesses and methods may be implemented in differing order.Furthermore, the outlined steps and operations are only provided asexamples, and some of the steps and operations may be optional, combinedinto fewer steps and operations, or expanded into additional steps andoperations without detracting from the disclosed embodiments.

FIG. 10 is a flow chart of an example method 1000 of chip-levelintegration of a diffuser in a light source according to at least oneembodiment described in the present disclosure. Although illustrated asdiscrete blocks, various blocks in FIG. 10 may be divided intoadditional blocks, combined into fewer blocks, or eliminated, dependingon the desired implementation.

The method 1000 may begin at block 1002 in which an epitaxy layer may begrown. The epitaxy layer may be grown on a first surface of a substrate.The substrate may include the first surface and a second surface that isopposite the first surface. At block 1004, one or more optical elementsmay be formed in the epitaxy layer. The one or more optical elements maybe formed in the epitaxy layer such that optical signals transmitted bythe one or more optical elements propagate through the substrate in adirection towards the second surface.

At block 1006, at least a portion of the integrated diffuser may beformed on a polymer surface. At block 1008, the polymer surface may beattached to the second surface of the substrate. In some embodiments,the integrated diffuser may be comprised of an ultra violet (UV) curablepolymer. In these and other embodiments, the integrated diffuser may begenerated using a master UV stamp, for instance. Additionally, in someembodiments, the integrated diffuser may be comprised of athermoplastic. In these and other embodiments, the integrated diffusermay be generated using a heated stamp that melts a surface of thethermoplastic.

At block 1010, the integrated diffuser may be positioned directly on thesecond surface. The integrated diffuser may be positioned on the secondsurface such that the integrated diffuser is configured to receive thetransmitted optical signals directly from the substrate after theoptical signal propagates through the substrate and to control aparticular profile of a resultant beam of the optical signal after theoptical signal propagates through the integrated diffuser.

Unless specific arrangements described herein are mutually exclusivewith one another, the various implementations described herein can becombined to enhance system functionality or to produce complementaryfunctions. Likewise, aspects of the implementations may be implementedin standalone arrangements. Thus, the above description has been givenby way of example only and modification in detail may be made within thescope of the present invention.

With respect to the use of substantially any plural or singular termsherein, those having skill in the art can translate from the plural tothe singular or from the singular to the plural as is appropriate to thecontext or application. The various singular/plural permutations may beexpressly set forth herein for sake of clarity. A reference to anelement in the singular is not intended to mean “one and only one”unless specifically stated, but rather “one or more.” Moreover, nothingdisclosed herein is intended to be dedicated to the public regardless ofwhether such disclosure is explicitly recited in the above description.

In general, terms used herein, and especially in the appended claims(e.g., bodies of the appended claims) are generally intended as “open”terms (e.g., the term “including” should be interpreted as “includingbut not limited to,” the term “having” should be interpreted as “havingat least,” the term “includes” should be interpreted as “includes but isnot limited to,” etc.). Furthermore, in those instances where aconvention analogous to “at least one of A, B, and C, etc.” is used, ingeneral, such a construction is intended in the sense one having skillin the art would understand the convention (e.g., “a system having atleast one of A, B, and C” would include but not be limited to systemsthat include A alone, B alone, C alone, A and B together, A and Ctogether, B and C together, or A, B, and C together, etc.). Also, aphrase presenting two or more alternative terms, whether in thedescription, claims, or drawings, should be understood to include one ofthe terms, either of the terms, or both terms. For example, the phrase“A or B” will be understood to include the possibilities of “A” or “B”or “A and B.”

The present invention may be embodied in other specific forms withoutdeparting from its spirit or essential characteristics. The describedembodiments are to be considered in all respects only as illustrativeand not restrictive. The scope of the invention is, therefore, indicatedby the appended claims rather than by the foregoing description. Allchanges which come within the meaning and range of equivalency of theclaims are to be embraced within their scope.

What is claimed is:
 1. A light source, comprising: a substrate includinga first surface and a second surface positioned opposite the firstsurface; an epitaxy layer positioned on the first surface of thesubstrate; an optical element formed in the epitaxy layer, the opticalelement positioned such that an optical signal transmitted thereby isdirected toward the substrate; and a diffuser configured to receive theoptical signal and to control a particular profile of a resultant beamof the optical signal after the optical signal propagates through thediffuser, wherein the diffuser includes a plurality of lenslets carriedby the substrate, and one or more of the lenslets is refractive ordiffractive.
 2. The light source of claim 1, wherein the plurality oflenslets are positioned in a pseudorandom arrangement.
 3. The lightsource of claim 1, wherein one or more of the plurality of lenslets ispositioned directly on the second surface of the substrate.
 4. The lightsource of claim 3, wherein one or more of the plurality of lenslets isetched directly into the second surface of the substrate.
 5. The lightsource of claim 1, wherein one or more of the plurality of lenslets isetched directly into the second surface of the substrate.
 6. The lightsource of claim 5, further comprising a polymer overlay positioned overthe one more of the plurality of lenslets etched directly into thesecond surface of the substrate.
 7. The light source of claim 1, whereinat least one of the plurality of lenslets is diffractive and at leastone of the plurality of lenslets is refractive.
 8. The light source ofclaim 1, wherein the diffuser is further configured such that theparticular profile of the resultant beam is controlled over two axessuch that the particular profile includes a first dimension in a firstdirection that is aligned with a first of the two axes and a seconddimension in a second direction that is aligned with a second of the twoaxes.
 9. The light source of claim 1, wherein the plurality of lensletsinclude two or more pseudorandom focal lengths.
 10. A light source,comprising: a substrate including a first surface and a second surfacepositioned opposite of the first surface and being configured for anoptical signal to pass therethrough; and a diffuser configured toreceive an optical signal and to control a particular profile of aresultant beam of the optical signal over two axes after the opticalsignal propagates through the diffuser, wherein the diffuser is carriedby the substrate and includes a plurality of lenslets pseudorandomlyarranged relative to one another.
 11. The light source of claim 10,further comprising: an epitaxy layer positioned on the first surface ofthe substrate; and an optical element formed in the epitaxy layer, theoptical element positioned such that an optical signal transmittedthereby is directed toward the substrate; wherein the optical element isimprecisely aligned with the diffuser.
 12. The light source of claim 10,wherein the plurality of lenslets include two or more pseudorandom focallengths.
 13. The light source of claim 10, wherein one or more of thelenslets is positioned directly on the second surface of the substrate.14. The light source of claim 10, wherein one or more of the lenslets isetched directly into the second surface of the substrate.
 15. The lightsource of claim 10, wherein one or more of the lenslets is formed in apolymer coupled to the second surface of the substrate.
 16. The lightsource of claim 10, wherein the plurality of lenslets include two ormore pseudorandom focal lengths.
 17. A method, comprising: growing anepitaxy layer on a first surface of a substrate, the substrate includingthe first surface and a second surface positioned opposite the firstsurface; forming an optical element in the epitaxy layer such that anoptical signal transmitted by the optical element is directed toward thesubstrate; and pseudorandomly arranging a plurality of lenslets on thesubstrate, wherein the plurality of lenslets are configured to receivethe optical signal transmitted by the optical element and to control aparticular profile of a resultant beam of the optical signal after theoptical signal propagates through the lenslets.
 18. The method of claim17, further comprising at least one of etching one or more of thelenslets directly into the second surface of the substrate and attachingone or more of the lenslets directly on the second surface of thesubstrate.
 19. The method of claim 17, further comprising attaching apolymer including one or more of the plurality of lenslets to thesubstrate.
 20. The method of claim 17, wherein the plurality of lensletsare pseudorandomly arranged directly on or into the second surface ofthe substrate.